The same thing happened to my son at the same age. For him,it turned out to be the laundry detergent they were using at his new daycare. He otherwise didn't have sensitive skin, but for some reason he reacted to it. It took awhile to figure out what it was, but he was always fine in the morning, had spots by the end of the day (after he napped in his crib with a sheet at daycare), and they always faded by bedtime. I just started washing his bedding at home, and he was fine. It sounds similar to your situation, but your son could also be stressed out by the storm or the new daycare. The best advice I can suggest is to see if it happens again.